Feat/linked host switching

[LCozatl]

Summary

Add keyboard-initiated Easy-Switch synchronization for linked Logitech pointing devices.

When an Easy-Switch key is pressed on a compatible keyboard, OpenLogi switches every configured pointing device to the corresponding host channel before switching the keyboard. This allows the
configured devices to move together between hosts.

Implementing this feature also exposed a HID++ capture lifecycle issue: a device returning after an Easy-Switch transition retained its route but did not restart capture. The capture target now
follows the device's online state without resetting its DPI-cycle position.

Changes

• openlogi-core

  • Add host_switch_targets to the per-device TOML configuration.
  • Support serialization and deserialization of physical target device keys.

• openlogi-hid

  • Detect host-switch controls exposed through HID++ reprogrammable controls.
  • Support diverted-control and analytics-event reporting modes.
  • Switch configured pointing devices before switching the initiating keyboard.
  • Reuse the receiver channel when linked devices share a Bolt or Unifying receiver.
  • Restore temporarily modified control reporting when the session ends.

• openlogi-agent-core

  • Resolve configured host-switch links against the current device inventory.
  • Rebuild links when the configuration or device availability changes.
  • Require the initiating keyboard to be online while preserving routes for sleeping target devices.
  • Restart HID++ capture when a device returns without resetting its DPI-cycle position.
  • Ignore missing targets and empty link configurations.
  • Add coverage for host-switch links and capture lifecycle transitions.

• Documentation

  • Document host_switch_targets and provide a TOML configuration example.

Testing

Automated verification:

• devenv tasks run openlogi:check

OpenLogi hardware testing was performed on Linux using the OpenLogi 0.6.22 RPM package with:

• MX Master 3S, firmware 22.1.6, linked to an MX Mechanical, firmware 71.3.21.
• MX Master 3S, firmware 22.1.6, linked to an MX Mechanical Mini, firmware 72.3.14.

Both combinations were tested with the new host-switch synchronization functionality.

Cross-agent behavior was additionally checked using the official Logi Options+ 2.5 client:

• Windows with a Bolt receiver.
• macOS over Bluetooth.

These checks confirmed that the devices can switch between corresponding host channels regardless of which agent manages them. OpenLogi itself was not runtime-tested on Windows or macOS as part
of this change.

Known limitations

• Older keyboard firmware may not expose the HID++ controls or events required by this feature.
• Every linked device must already be paired with the corresponding channel on each host.
• The host-switch link must be configured on every computer from which the keyboard can initiate a switch.

Note

Depends on #453 for the online-aware input capture selection behavior. This branch will be rebased onto master after that PR merges, then re-tested before being marked ready for review.

[greptile-apps]

Greptile Summary

The PR adds synchronized Easy-Switch handling for linked pointing devices and updates receiver arbitration, channel reuse, configuration, and capture lifecycle behavior.

• Adds persistent keyboard-to-pointing-device host-switch links.
• Detects and temporarily configures HID++ host controls.
• Coordinates linked host transitions with pairing, capture, and ordinary device I/O.
• Restarts capture as the selected device moves offline and online.

Confidence Score: 4/5

The PR does not yet appear safe to merge because valid host-key requests can still be discarded and concurrent receiver sessions can still split HID++ reports.

Session reconciliation removes generation state before queued key-press completions are consumed, while gesture capture and host switching continue to use independent channel stores under simultaneous shared receiver leases.

Files Needing Attention: crates/openlogi-agent-core/src/watchers/host_switch.rs, crates/openlogi-agent-core/src/receiver_access.rs, crates/openlogi-hid/src/channel_pool.rs

Important Files Changed

Filename	Overview
crates/openlogi-agent-core/src/watchers/host_switch.rs	Adds generation-tagged host-switch session reconciliation and coordinated transitions.
crates/openlogi-agent-core/src/receiver_access.rs	Replaces exclusive capture ownership with shared session leases and reason-tagged exclusive operations.
crates/openlogi-hid/src/host_switch.rs	Implements host-control discovery, rollback-safe temporary reporting changes, event capture, and ordered device switching.
crates/openlogi-hid/src/channel_pool.rs	Adds transport-based channel reuse for host-switch sessions.
crates/openlogi-agent-core/src/orchestrator.rs	Resolves configured host-switch links and synchronizes capture targets with online state.
crates/openlogi-core/src/config/device.rs	Adds backward-compatible serialization of per-device host-switch targets.

_{Reviews (6): Last reviewed commit: "style: rustfmt after host-switch rebase" | Re-trigger Greptile}

[LCozatl]

@greptileai